The gun will shoot, but not extract the round. After firing the spent shell remains chambered, slide closed, extractor still engaging the rim. I can manually slingshot the slide and the round extracts and ejects cleanly. Next round strips off the mag and loads just fine. It acts just like a gas gun (like a FAL, AR or AK) with the gas port plugged.

I'm thinking the chamber is a bit rough and the brass is grabbing on to it as it expands when the bullet is fired. Once the brass cools a second or two later, it contracts and allows me to extract it by manually cycling the slide. Does this seem likely?